SIP lost registration event!


I am using a UCM6208 control unit with a Siemens C430 telephone and every 2 minutes the following event appears in the central unit log

SIP lost registration event! extension: PJSIP/308,username: PJSIP/308

Because of this the communication is cut, is there any clue where to start looking?
Thank you


The best place to start is to run a packet capture from within the UCM. If this is happening every few minutes as you mention, it shouldn’t be hard to track down the issue that is occurring.

One thing you could try is under PBX -> Extensions, edit your extension and check the “Enable Keep Alive” checkbox…this could fix the problem, but it’s hard to say.

Even though you are supposedly losing registration, does hte phone work with no issues? Could be a phantom issue, though I doubt it.



I have the same problem but it happens like every hour. When this happen the device can call other extensions but the other extensions can’t reach it. It’s really frustrating. I have enabled the Keep Alive with 60s interval but it’s still not working. Can any one help?


Every time I’ve run into this, it’s ended up being a cable problem.

Might not be the only reason, just the only reason I’ve run into.

Don’t just test the line, call someone who can certify it. Although, you could just swap for new patch cords on the phone and in server room first and do a visual inspection of the wall jack ect.